to ascertain the number of flame cells; however, it can be said that their 

 number is considerably larger than 20. The sizes of these cells are 

 about 0. 005 mm. The attaching disc is sharply delineated from the rest 

 of the body and is somewhat smaller in width. The armature of the disc 

 consists of 14 edge hooks of the usual shape for Dactylogyridae with a 

 length of about 0. 012 mm among D. aculeatum and about 0. 008 mm among 

 D. similis. In such a fashion, all four middle hooks, three connecting 

 plates, and both attaching plates are incepted and developed already 

 after the attachment of the larvae to its host. 



p. 167 



10. The development of Lamellodiscus Johnston and Tiegs 



The genus Lamellodiscus (Fig. 34) is very close to Diplec - 

 tanum Diesing and differs mainly in that its supplementary discs carry 

 not a number of stick-shaped formations but a number of concentrically 

 disposed chitinous threads (Fig. 183). During our work at the Karadaga 

 Biological Station in July-August, 1947 we obtained free-swimming larvae 

 of two species (L. elegans Bychowsky, and L. fraternus Bychowsky) and 

 studied the development of one of them more in detail. The material for 

 this w^ork was collected from the gills of Sargus annularis (L. ). 



The free-swimming larvae of both species emerge from the 

 eggs three or four days after the deposition of the latter by the mother 

 individual. The larvae are torpedo-shaped just as the larvae of 



Fig. 183. Lamellodiscus elegans Bychowsky, middle hooks, their 

 connecting apparatus and chitinous armature of the supplementary discs 

 of an adult worm from Sargus annularis (L. ) from the region of 

 Karadaga (Black Sea). 



Diplectantim which they greatly resemble both in exterior shape and in- 

 terior structure (Fig. 184). The sizes of the larvae of both species are 

 the same: their length is about 0. 09 mm with a width of 0. 03 mm (the 



180 



